1. Field of the Invention
The present invention relates to an indoor positioning method, and particularly relates to an indoor positioning method and an indoor positioning system for positioning a portable electronic device in an indoor environment and an indoor map establishing device thereof.
2. Description of Related Art
As wireless mobile devices gain popularity, more and more users conduct the activities in their daily life through mobile devices, and there are more and more places offering wireless network connection. Since the environment of wireless network has become more and more matured, various device manufacturers now shift focus on value-adding applications of the environment of wireless network, and one example of such applications is to provide position sensing service that offers position information. Through the position sensing service, the user can be informed with various nearby information and services and is able to quickly find his/her destination. Besides, business owners or service providers would hope to sense based on the position sensing service, so as to send information (e.g., advertisements) to the users when the users are in their business locations (e.g., malls, restaurants, parking lots, department stores, and the like). In view of the needs, it is important and necessary to provide an indoor positioning and navigating system capable of quick indoor positioning and navigating, so as to exchange the data between the business owners or service providers and the users.
Conventional commercial positioning systems, such as the Global Positioning System (GPS), are basically applicable for outdoor positioning. Such systems exhibit higher positioning accuracy and a faster positioning speed in an environment with preferable signal strength. Since satellite signals are significantly attenuated indoor, it is more challenging to use the outdoor positioning systems for indoor positioning. Currently, conventional indoor three-dimensional object positioning or tracking techniques are also under limitations such as unable to receive GPS signals, and thus adopt a user device having a wireless communication function (e.g., Bluetooth, WIFI, etc.) to transmit signals and rely on a signal strength indicator value to determine a distance with respect to a nearby object, or dispose a tag having a wireless communication function (ex. NFC tags) to an indoor object, so as to read and write relevant data through radio signals and identify a specific target by the technique of Near Field Communication. However, since these three-dimensional object positioning techniques are also based on signal reception and determination of signal strength, these techniques are also prone to the environmental influences that make the signals unstable and thus affect the accuracy of three-dimensional object positioning. Besides, the radio frequency identification function is only able to identify a specific target with a tag, and is unable to determine the distance between the user device and the object in the surrounding. In addition, the quantity of tags disposed is also subject to the budget.
It is also common to position based on a base station. For example, a positioning device (e.g., the user's mobile device) may calculate the current position by calculating the time for a signal to arrive at the base station. However, since the error of such method may be as high as hundreds of meters, such method is not suitable in the scenario of indoor positioning.
Therefore, a positioning method based on the wireless network is more suitable for an outdoor space that is more spacious, such as a stadium or an outdoor space without obstacles, and the positioning effect of such method in a space within a building, such as an indoor space or a hallway, is not as desirable. Besides, these techniques are suitable for two-dimensional positioning, and not capable of accurate three-dimensional positioning. Thus, the positioning techniques are unable to meet the needs for indoor positioning, such that currently no indoor positioning system can be used by the mass.